Formation of some devices on substrates (e.g., STT-RAM) requires multiple layers of thin films which are deposited in a deposition chamber, such as a physical vapor deposition (PVD) chamber. In some embodiments, the substrate needs to be rotated during the deposition process to obtain good film uniformity. For example, when the deposition process uses multiple cathodes and targets that are disposed off-axis with respect to the substrate to deposit the different materials, the substrate needs to be rotated to ensure good film uniformity. Deposition of some layers may also require the substrate to be at a low temperature and, subsequently, annealed. However, typical substrate supports include a pedestal that retains temperature when heated to high temperatures. As such, the pedestal must be allowed to cool down before any further low temperature processes are conducted. As a result, throughput is negatively impacted.
To avoid such chamber downtime, the substrate may be transferred to a separate anneal chamber, which may be coupled to the same cluster tool as the PVD chamber. However, the inventors have observed a need for in-situ anneal to improve the throughput of the PVD chamber. The inventors have also observed a need for an ex-situ anneal chamber that heats a substrate in a more uniform manner than conventional anneal chambers.
Therefore, the inventors have provided embodiments of improved methods and apparatus for processing substrates.